Artha is a handy thesaurus based on WordNet with distinct features like global hot key look up, passive desktop notification, regular expression based search, etc. Artha may be used as a free open-source replacement/clone to the proprietary WordWeb Pro thesaurus (which is also based on WordNet) on Unix-like and Windows operating systems.

taggrepper is a simple program to match several tags of media files, currently Ogg Vorbis and MP3 files, against specified regular expressions. It works on individual files as well as recursively traversing directory trees for media files.

krep is a file viewer that lets you filter a file's content using regular expressions. You can add and remove filtering conditions without getting out of the work flow. If you do not give a file, standard input is shown. If the given file changes, krep reloads it.

Regular Expression Builder for Java (reb4j) is a simple set of classes that encapsulates the regular expressions used by java.util.regex.Pattern and provides facilities for composing larger expressions from sub-expressions. It effectively provides a way to build regular expressions without the risk of encountering PatternSyntaxExceptions at runtime.

Email Address Validator is a PHP class that allows the developer to validate email addresses according to the RFC 5321 or RFC 5322 standards. It can also check to see if the domain can be resolved to MX RRs. Acceptable local-parts include dot-atom, quoted string, and obsolete. Acceptable domains include domain name, IPv4 address, IPv6 address, and IPv4-mapped IPv6 address. Folding white spaces and nested comments are also supported.

foma is a compiler, programming language, and C library for constructing finite-state automata and transducers for various uses. It has specific support for many natural language processing applications such as producing morphological analyzers. Although NLP applications are probably the main use of foma, it is sufficiently generic to use for a large number of purposes. It comes with an xfst-compatible interface and regular expression language. The library contains efficient implementations of all classical automata/transducer algorithms: determinization, minimization, epsilon-removal, composition, and boolean operations. More advanced construction methods are also available: context restriction, quotients, first-order regular logic, transducers from replacement rules, etc.

Notepas is a multi-platform text editor written in Lazarus which can be compiled for multiple platforms and widget sets using the advanced native Free Pascal Compiler. Aimed at developers, it has some functions usually not found in other text editors and introduces some new exclusive features.